DC-to-DC converters are generally switch-mode power supplies that convert one DC voltage to another. Some DC-to-DC converters, step-up converters, generate a higher voltage from a lower input voltage, and other DC-to-DC converters, step-down converters, generate a lower voltage from a higher input voltage. One type of step-down switch mode power supply is known as a Buck converter.
A switching power supply typically includes an energy-storage inductor, and a regulation system in which a control element, for example, a transistor switch, is rapidly switched on and off. Pulses for switching the transistor on and off may be produced by an oscillator/error amplifier/pulse-width modulator network. While the transistor is switched on, energy may be pumped into the inductor and stored in a magnetic field. When the transistor is switched OFF, the energy stored in the inductor is directed into a filter and load. Filter output may be provided to an error amplifier that controls generation of pulses for switching the transistor on and off.
Multiphase power conversion is an improvement over single phase conversion. A multiphase converter includes a number of parallel power stages that drive a common load. By phase shifting the control signals to the converter power stages the multiphase converter provides several advantages over a single power stage including lower current ripple on the input and output capacitors, faster transient response to load steps, improved power handling capabilities, and higher system efficiency. Multiphase converters distribute the power and load current, which results in smaller and lower cost transistors with fewer input and output capacitors.